
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* block 不设样式--宽 100% 高 内容 */
        /* 设置样式 */
        div{
            box-sizing:border-box;
        }
        .box1{
            width: 300px;
            height: 300px;
            padding-top: 100px;
            border: 20px solid red;
        }
        .box1 .box2{
            width: 100px;
            height: 100px;
            /* margin-top: 100px; */
            background-color: blue;
        }
    </style>
</head>
<body>
    <div class="box1">
        <div class="box2">
            logo
        </div>
    </div>
</body>
</html>